When I was still in contact with my axbf he told me on New Year's Eve that it was the start of a new life for him- he was done with drinking, he was going to get healthy, etc etc etc.
I said good for him and I really hoped that he actually followed through with it although he didn't need new year to change his life it could be done at any point. He told me in response to that I was being negative, I never encouraged him etc etc etc. I thought I was just being honest and realistic and after months and months of the alcohol and abuse I was entitled to be at least cautious.
I don't know if he is drunk or sober now as I cut contact but I do know that his new life didn't begin after new year as he was on and off the wagon for the following months culminating in me having to go no contact with him.
I do hope for your sake that he means what he says but I am glad that you are feeling strong to stand your position either way, and are not expecting miracles like I did so many times. Good for you, and stay strong.